La Terre Adélie :
> Présentation
> Histoire
> Carnet de voyage
La base Dumont d'Urville :
> Présentation
> Visite
> La base Marret
Environnement :
> Faune
> Protection
Les missions polaires :
> Vous aussi hivernez !
> La mid-winter
Informations sur le site :
> Pourquoi ce site ?
> Copyright


>> Aurora australis <<

The polar lights are a phenomenon which occurs in the upper atmosphere and which appears during the night by the appearance in the sky of gleams of which the form and the intensity can evolve quickly and whose color is in general between the blue-green and the yellow, more rarely towards the red.
Frequent in the areas of high latitudes, they appear exceptionally with the average latitudes, in period of strong solar activity. According to the hemisphere where they are observed, they bear the name of aurora borealis (Northern hemisphere) or australis (Southern hemisphere).

Aurora australis
Aurora australis - Terre Adélie, june 2006.
© Samuel Blanc


Screens saver to download here.

More pictures here.

Principle of formation:
The sun emits a flow of electrically charged particles continuously called solar wind. By reaching the Earth, the majority of these particles are deviated by the magnetosphere; the magnetic field of the Earth, and take again their race in space. However, when solar wind is particularly intense, as it is the case at the time of a solar storm, a great number of particles enter the atmosphere while following the field of force of the terrestrial geomagnetic poles. The energy particles enter then in collision with the atoms of the upper atmosphere which release the surplus of energy in the form of light, which causes the polar lights.

This intense magnetic activity, is found on the various readings taken like below at the time of the episode of June 15, 2006 out of Adelie Coast. One notices the strong variations of the magnetic field in the neighbourhoods of 3:00pm (hour universal time) that is to say 11:00pm (standard times), hour to which was observed a superb dawn.

Magnetic field
Variations of the magnetic field at the time of the aurora australis of June 15, 2006.


Aurora australis
Aurora australis - Terre Adélie, june 2006.
© Samuel Blanc

Aurora australis
Aurora australis - Terre Adélie, march 2006.
© Samuel Blanc

Multimédia :
> Galeries de photos
> Ambiances sonores
> Séquences vidéos
> Documents historiques
> Médias
> A télécharger
Documentation :
> L'Astrolabe, le navire
> Bibliographie polaire
> Citations
> Les années polaires
> Lexique polaire
> Liens
Météo, banquise et autre :
> Les aurores australes
> Le vent catabatique
> Météo et climat
> La banquise
> Les rythmes du soleil
Saisissez ici un terme que vous recherchez sur le site :    

© / 2005-2013

Les textes, photos, sons et vidéos de ce site, sauf mention contraire, appartiennent à leur auteur Samuel Blanc, et sont protégés par les lois internationales sur le copyright. Merci de me contacter pour toute utilisation.